Bicycle racing is a highly competitive sport where riders are competing for the best possible times. Bicycles are being designed to assist the riders to achieve their best. One way to assist the rider is to design a bicycle that is as light as possible without losing the stiffness, strength or wear resistance.
In the past, bicycle fork steerer tubes were made out of metal. Bicycle fork steerer tubes were originally typically made out of steel but as more emphasis was placed on reducing the weight of bicycles some bicycle fork steerer tubes were made out of aluminum. Metal bicycle fork steerer tubes are both strong and resilient but do not provide as lightweight a design as is desired for bicycle racing.
To further reduce the weight of bicycles, some bicycle fork steerer tubes have been constructed out of non-metallic materials including notably carbon fibre and various fibres or combinations of fibres such as glass, Kevlar and carbon. These various fibres are placed in a polymer or other matrix to form the bicycle fork steerer tube structure. Such fibre composite bicycle fork steerer tubes can be lighter weight than traditional metal bicycle fork steerer tubes.
While fibre composite bicycle fork steerer tubes are lighter, the fibre composite bicycle fork steerer tubes suffer the disadvantage that they do not have all of the beneficial properties of the metal tubes including the strength, rigidity or wear resistance. The reduction in strength and wear resistance can cause the fibre composite bicycle fork steerer tube to be damaged more easily than the metal bicycle fork steerer tubes. Furthermore, the fibre composite bicycle fork steerer tubes have the disadvantage that they are prone to failure if the surfaces of the tubes are damaged. These factors can disadvantageously affect the performance, reliability and length of service of the fibre composite bicycle fork steerer tubes.
Bicycle fork steerer tubes are designed so that bicycle handlebars and other suitable devices can be clamped to the bicycle fork steerer tube. When the clamp is tightened around the bicycle fork steerer tube high loads are created on the steerer tube weakening the structure, such loads typically include point loads created at the location where the clamp is tightened potentially causing damage.
While fibre composite materials can create strong structures, the strength depends on the direction of the fibres and they tend to be sensitive to point loads and impacts.
A metal tube, on the other hand generally has essentially equal strength characteristics in all desired directions and higher tolerance for impact and point loads, but typically will weigh more than a fibre composite tube.